Safety coupling for screw joints



Sept. 11, 1934. J 5 K SAFETY COUPLING FOR SCREW JOINTS INVENTOR.

ATTORNEY.

l/lI/Illl Filed Feb a F W Patented Sept. 11, 1934 g UNITED STATES PATENT QFFECE SAFETY COUPLING FOR SCREW JOINTS Julius S. Beck, Los Angeles, Calif., assignor to James A. Kammerdiner, Los Angeles, Galif.

Application February 24, 1933, Serial No. 658,292 6 Claims. (01. 255-27) This invention relates to a coupling adapted rotary movement and thereby prevent uncoufor placing in a string of rods, or a tubular string pling by rotation or to longitudinally position of pipe and capable of use to clutch the joint the members to enable rotary movement of the sections together or release them by longitudinal members or" the coupling and uncoupling; means positioning of the members of the coupling. to releasably hold the members longitudinally As illustrative of a specific embodiment of the in clutched position and declutchable by a longiinvention, a coupling adaptable for use in well tudinal pull oh the tubular string in which the drill pipe employed in rotary drilling is described coupling is placed; and details of structure conin the subjoined specification. In the operation tributing to the before mentioned functional re of such strings of drill pipe, it is desirable and lationships. 65 the usual practice to provide tool joints at in- These objects are accomplished by means of tervals which may be readily broken or. unthe embodiment 'of' my invention illustrated in. coupled when desired. Right hand threads are the accompanying drawing, in which:--- commonly employed in the tool joints. If it is Fig. 1 is a longitudinal section through acoudesired to break a joint, it is the conventional pling as seen on the irregular. plane indicated 70 practice to back up to the left. However, with by the lines 1-1 in Figs. 3 to 7 inclusive, the

a number of tool joints in the string, it is imcoupling being shown with parts disposed in possible to predetermine which joint will be unclutched position; Fig. 2 is a View like Fig. 1

coupled. It is understood that for certain opershowing the parts in declutched position; Figs.

ations such as fishing, left hand threaded tool 3 to '7 inclusive show sections indicated by planes joints are employed. To uncouple a string havcorrespondinglynumbered in Fig. 1; and Fig. 8

ing left hand threaded tool joints, uncoupling is a longitudinal View illustrating a drill string may be effected by backing up to the right. As provided with a number of right hand threaded with the right hand threaded tool joints, it is tool joints, a drill bit and a safety coupling above impossible to predetermine at what joint uncouthe drill collar of a bit. pling will occur in left hand threaded tool joints. Referring more particularly to the drawing, It is often desirable in wells to break the joint A indicates the female member of my improved at a particular place. For illustration, with a coupling and B the male member. The female rotary boring tool at the end of a drill string, member hasa body 10 provided with a left hand 30 the boring tool may become stuck and it is found threaded tapered bore 11 preferably having a advisable to disconnect the drill string immedifast thread and at the bottom end is provided ately above the boring tool. This is attempted with a right hand threaded pin 12 whereby it by backing off. However, in most instances the may be mounted in a corresponding box as dedrill string uncouples immediately below the rosired in a string of drill pipe. At the upper end 35 tary table leaving the drill string between the are jaws 14 forming a portion of a jaw clutch. table and boring tool in the hole. The mud used The male member comprises a tubular body 15 in rotary drilling for circulation settles around having a right hand threaded tapered box 16 the drill string, freezing it in the hole and at the upper end for connection to a pin or like requiring a very expensive operation for its remember in the string of drill pipe. At its lower 40 moval. The present invention relates to a couend, the body 15 is provided with jaws 17 for pling which may be inserted at any desired point engagement between jaws 14 when the coupling in the drill string and may be clutched to preis in contracted position as shown in Fig. 1. It vent uncoupling during normal operation of the is also provided with a shaft having a left hand string in both directions, but by longitudinal threaded pin portion to be engaged with the 45 movement of the string may be declutched to box 11 of member A.

enable uncoupling by rotation in the same direc- The body 15 is provided with a bore forming tion as in the boring operation. Although a a continuation of the tapered bore 16. This specific use of the present invention has been bore is threaded at 18 and receives therein a dedescribed, it will be understood that it is not tention barrel 19. The barrel may be locked 50 limited to such specific use. in position by a set screw 20. Below the thread- The objects of this invention are to provide a ed portion 18 of the bore of member B is an. coupling member for a screw joint having any enlarged portion 21. The barrel 19 spans the or all of the following featuresz-Means to openlarged portion 21 and is provided with longitionally position the male and female members tudinally extending slits 22. The slits extend of the coupling so as to provide a clutch against short of the ends of the barrel so that a barrel is formed which maybe expanded laterally. On the inner bore of the barrel are rounded catch portions 23 which project inwardly and have inclined faces. Adjacent the clutch jaws 17, the bore is threaded to receive a drive bushing 24. which may be held in position by a set screw 25. The bushing 24 is provided with key Ways 26 extending longitudinally thereof.

Mounted within the bore of body 15 is a tubular shaft 27 threaded so that it may be engaged with the threads of box 11. It is also provided with splines 28 which are disposed within the key ways 26 so that shaft 27 is held against rotation with respect to the body 15 but is permitted sliding movement. The upper end of the shaft is enlarged externally to provide an abut ment 29 whose lower face may engage the upper face of bushing 24 when the coupling is expanded as shown in Fig. 2. The bore of shaft 27 is threaded to receive a telescopic extension 30. The extension 30 has a tapered seat 31 forming a wedge adjacent its upper end, the upper end being externally enlarged to provide a slip fit with the bore of the upper portion of bushing 19 whereby a closed water course is formed through the coupling in both expanded and contracted positions. The upper portion of the bore of shaft 27 is enlarged to receive a detention ferrule 32 which is threaded therein and is provided with strips 33. The strips 33 rest against the wedge seat 31 at their outer ends and have inclined catch surfaces 34 to coact with the inclined catch surfaces 23 of the barrel.

trated as composed of stands C connected by j" 23 and 34.

tool inserted through the upper end of the bore right hand threaded tool joints D. A 'drillbit E is mounted in the string and connected thereto by my safety coupling F. With the parts of safety coupling F in positions shown in Fig. 1,

the jaw clutch is in clutching position, jaws l l being disposed between jaws 17. The shaft 2'7 is in retracted position being releasably held in this position by strips 33 engaging barrel '19 at the coacting inclined surfaces on catch portions an axial pull is exerted on the drill string causing barrel 19 to deflect outwardly and release strips 33, the inclined surfaces passing and enabling the shaft to be projected as shown in Fig. 2. In this position the jaw clutch is released and the coupling may be broken by turning the drill string to the right unscrewing pin 2'! from the member A while the tool joint D and other couplings will tend to tighten but not unscrew. An, adjustment can be made as to the tension required for release by turning the telescopic exof body 15 and screwing the extension 30 up or down at its threaded connection 36, xvith the shaft body to raise or lower the wedge seat and thereby decreaseror increase the outside diameter of the'strip member 32.v The space 37 indicates clearance enabling movement of the extension. Thus, the pull required on the coupling to cause the detention means formed by barrel 19 and ferrule 32 to release, may be adjusted.

If it is desired to break the joint,

What I claim is:--

l. A longitudinally expansible and contractible coupling having threaded ends for connection to a string, said ends being threaded in the same direction, said coupling comprising a male memher having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide clutch means on said members for clutching engagement on con traction declutching on expansion of said coupling; detention means between said shaft and its companion member to hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said members to declutched position, said pin portion and said box.

portion being positioned to be engageable in in declutched position.

2. A longitudinally expansible and contract'ible coupling having threaded ends for connection to a string, said ends being threaded in the same.

direction, said coupling comprising a male memher having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide clutch means on said members for clutching engagement on contraction and declutching on expansion of said coupling; said shaft being limited in its retraction to enable the pin portion to be positively abutted against and engaged with said box portion when said clutch means is disengaged; detention means between said shaft and its companion. member to hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said members to declutched position, said pin portion and said box portion being positioned to be engageable in clutched position and to be-threadedly meshed in declutched position.

3. A string for use in a well comprising section secured by threaded couplings having threads extending in one direction, a longitudinally expansible and contractible coupling comprising a male member having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said.

members to declutched position, said pin portion and said box portion being positioned to be engageable in clutched position and to be threadedly meshed in declutched position.

4. A string for use in a well, comprising sections secured by threaded couplings having threads extending in one direction, a longitudinally expansible and contractible coupling comprising a male member having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide clutch means on said members for clutching engagement on contraction and declutching on expansion of said coupling; said shaft being limited in its retraction to enable the pin portion to be positively abutted against and threadedly meshed with said box portion when said clutch means is disengaged; detention means between said shaft and its companion member having catch surfaces acting on one another, one of said surfaces being inclined to hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said members to declutched position, said pin portion and said box portion being positioned to be engageable in both positions.

5. A string for use in a well, comprising sections secured by threaded couplings having threads extending in one direction, a longitudinally expansible and contractible coupling comprising a male member having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide clutch means on said members for clutching engagement on contraction and declutching on expansion of said coupling; said shaft being limited in its retraction to enable the pin portion to be positively abutted against and threadedly meshed with said box portion when said clutch means is disengaged; detention means between said shaft and its companion member having catch surfaces acting on one another, one of said surfaces being inclined to hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said members to declutched position, said pin portion and said box portion being positioned to be engageable in both positions; and means to adjust the lateral engaging positions of said surfaces whereby to vary the axial pull required for release.

6. A string for use in well drilling, comprising sections secured by threaded couplings having threads extending in one direction, a longitudinally expansible and contractible coupling comprising a male member having a pin portion with a thread extending in a reverse direction and a female member having a box portion correspondingly threaded in relation to said pin portion for free engagement and release, one of said members having a shaft axially slidable for a limited distance and held against rotation therein and provided with one of said portions; side slide clutch means on said members for clutching engagement on contraction and declutching on expansion of said coupling; said shaft being limited in its retraction to enable the pin portion to be positively abutted against and threadedly meshed with said box portion when said clutch means is disengaged; detention means between said shaft and its companion member to hold said shaft in retracted position with said members in clutched position and releasable by exertion of an axial pull on said expansible and contractible coupling to enable expansion of said members to declutched position, said pin portion and said box portion being positioned to be engageable in both positions.

JULIUS S. BECK. 

